The European Union (EU) is said to be tired of enlargement – but how likely is itthat a candidate would be ready to join within 10, 15 or more years? Thisresearch forecasts how prospective members are likely able to perform inimplementing EU law until 2050. Using compliance data of all states from the2004, 2007 and 2013 accession rounds, as well as of five current/potentialcandidates, we construct an empirical model on candidates’ ability to complywith the acquis communautaire. We employ in-sample and out-of-sampletechniques to ensure high model prediction accuracy and, ultimately, forecastthe five candidates’ potential compliance levels in 2017–2050. Our researchshows that only one candidate might sufficiently be able to comply with theaccession criteria until 2023, while many are unlikely to be ready before themid-2030s. Focusing on prediction and forecasting, our contribution is givenby the research’s policy relevance and its methodological innovation.